Aegilops vavilovii (Zhuk.) Chennav., a rare species, was collected from Southeast Anatolia, Turkey. During the field studies of the project "Taxonomic revision of Tribe Triticeae in Turkey", Ae. vavilovii was accidentally recollected from three localities in Sanliurfa and Mardin provinces in 2007 and 2008, respectively. The main objective of this study is to shed light on the diagnostic characteristics of this rare species including its morphological, palynological and micro morphological features. Moreover, an emended and expanded description, distribution, phenology and ecology of this rare species are also provided. A. vavilovii and A. crassa are naturally found in the Southeastern part of Turkey and they share similar morphological features that caused a confused taxonomy. Pollen grains of A. vavilovii are heteropolar, monoporate and spheroidal (A/B: 1,13) typically as Poaceous. However, it generally, prefers clayish loam soils that are slightly alkaline (pH 7.7) with low organic content (1.54%). Although it is a rare species with very narrow area of distribution, very few samples have been represented in ex situ collections and the species has not been involved in any in situ conservation activities to save its genetic resources in Turkey.